{"product_id":"panasonic-br-a-replacement-battery-3v-1800mah-li-mno2","title":"Panasonic BR-A PLC Replacement Battery 3V 1800mAh Li-MnO2","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003ePanasonic BR-A — 3V Li-MnO2 Replacement Battery (BR-A, BR-A-TABS)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis Panasonic BR-A is a 3V, 1800mAh lithium manganese dioxide cell used as backup power in PLCs and industrial controllers. It maintains SRAM program memory and real-time clock functions when main power is interrupted. It covers BR-A and BR-A-TABS configurations used in memory backup and RTC applications across a wide range of control hardware.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBR-A and BR-A-TABS compatibility:\u003c\/strong\u003e\n    Both variants share the same 3V lithium manganese dioxide chemistry and cell dimensions. The TABS version adds solder tabs for direct PCB mounting — same electrochemical cell underneath. Swapping between tab and non-tab versions depends entirely on the controller's holder or solder-pad footprint.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed stable open-circuit voltage and verified the cell holds above the 2.5V SRAM retention threshold under low-current standby drain. The BMS in most PLCs does not actively manage this cell — it floats directly against the SRAM supply rail.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eHot-swap procedure for this cell:\u003c\/strong\u003e\n    Always replace this battery with the PLC powered on and in RUN mode. Removing the cell while the controller is off will collapse the SRAM supply rail immediately, erasing program memory. If the PLC was off during the swap, connect a programming device and reload the full program before restarting production.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePLC losing program memory after battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the BR-A is removed while the PLC is powered off or mid-shutdown. Without main power, the SRAM supply rail depends entirely on the battery. The instant the cell is disconnected, SRAM loses its hold voltage and the memory contents are gone — the cell swap itself causes the fault, not a bad battery. Always confirm the PLC is powered and in RUN mode before pulling the old cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBattery alarm not clearing after a confirmed good installation\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eMost PLCs latch the low-battery alarm in firmware and do not clear it automatically when a new cell is installed. The controller detects the alarm condition, sets a flag in non-volatile status memory, and holds it until a deliberate reset. Connect a programming device, navigate to the diagnostic or battery status register, and manually clear the fault flag. On some Mitsubishi and Omron units this is a one-click reset in the programming software's PLC diagnostics panel.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43415986077786,"sku":"BWCS-PLC180SL-1","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43415986110554,"sku":"BWCS-PLC180SL-2","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43415986143322,"sku":"BWCS-PLC180SL-3","price":31.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-PLC180SL-1.webp?v=1779758956","url":"https:\/\/batteryweb.com\/products\/panasonic-br-a-replacement-battery-3v-1800mah-li-mno2","provider":"BatteryWeb","version":"1.0","type":"link"}